Floor Controls; Power Brake System; Self Adjusting Brakes - GMC MOTORHOME 1978 Operating Manual

POWER BRAKE SYSTEM
This vehicle is equipped with a Dual Hy-
draulic Split System With Power Assist . It is
also equipped with disc type brakes on the front
wheels and drum type brakes on the tandem
rear wheels .
CAUTION
Driving through water deep enough to
wet the brakes may cause the brakes
not to work as well . As a result the
Motorhome will not slow down at the
usual rate, and it may pull to the right
or left. After checking to the rear for
other vehicles, apply the brakes lightly
to check whether this has happened .
To dry them quickly, lightly apply the
brakes . At the same time keep a safe
forward speed, with plenty of clear
space ahead, to the rear and to the
sides.
Do
this until the brakes return
to normal.
NOTICE: The brake system warning light is
covered on page 24 under "Instrument Panel
and Controls" in this section.
If power assist is lost because of a stalled
engine or other reasons, the brakes can nor-
mally still be applied with power assist at
least two times using reserve power.
" If the brake pedal is held down, the system
is designed to bring the vehicle to a full stop
on reserve power. However, the reserve
power is partly used up each time the brake
pedal is applied and released . Do not pump
the brakes when brake power assist has been
lost (except when needed to maintain steer-
ing control on slippery surfaces) .
Without power assist, the vehicle can still be
stopped by pushing much harder on the
brake pedal. However, the stopping distance
may be longer.
SELF-ADJUSTING BRAKES
The brakes on this vehicle (except for the
parking brake) are self-adjusting. They have
been designed so that periodic brake adjustment
is not required. The drum brakes adjust them-
selves when the brakes are firmly applied while
the vehicle is moving backwards.
FLOOR CONTROLS
2 1
The disc brakes adjust themselves each time
the brakes are used.
Thus, if the brake pedal goes down further
than normal due to a lack of adjustment,
drive backward and forward a few times.
Apply the brakes firmly when going each
way.
See your dealer if pedal height does not re-
turn to normal, or if there is a rapid increase
in pedal travel, which could be a sign of
other brake trouble. Also see your dealer if
the parking brake needs adjustment .
NOTICE: "Riding the brake" by resting your foot
on the brake pedal when not intending to brake
can cause overheated brakes . This can wear out
the brake linings faster and damage the brakes
themselves, as well as waste fuel.
NOTICE: Front disc brakes have a built-in wear
indicator that is designed to make a high pitched
squealing or cricket-like warning sound when the
bare linings are worn to where new linings are
needed. The sound will come and go, or be
heard all the time when the wheels are rolling,
but will stop when the brake pedal is pushed
down firmly. There are also several brake checks
listed in the Maintenance Schedule folder.
PARKING BRAKE
The amount of force needed to apply the
parking brake can be adjusted by turning the
knob on the upper end of the lever. This also
adjusts how strongly the brake itself is applied.
The greater the force needed at the lever, the
greater the degree of brake application.
CAUTION
The parking broke should be set be-
fore leaving the driver's seat . This will
help keep the vehicle from moving
unexpectedly which could result in
personal 'injury.
To set the parking brake, fully pull up the
handle on the floor near the left wall.
For better holding power, first press down
the regular brake pedal. Then hold it while
setting the parking brake.
e To release the parking brake, push the
handle down .
To help remind you, the "Park Brake" light